Fair value of financial instruments The following table sets forth the Company's assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2019 and 2018 (in thousands): | | | | | | | | | | | | | | | | | | Total | | Quoted prices in active markets (Level 1) | | Significant other observable inputs (Level 2) | | Significant unobservable inputs (Level 3) | December 31, 2019 | | | | | | | | Assets | | | | | | | | Cash equivalents | 39,971 |
| | 39,971 |
| | — |
| | — |
| Total assets | $ | 39,971 |
| | $ | 39,971 |
| | $ | — |
| | $ | — |
| | | | | | | | | Liabilities | | | | | | | | Warrant liability | 2,486 |
| | — |
| | — |
| | 2,486 |
| Total liabilities | $ | 2,486 |
| | $ | — |
| | $ | — |
| | $ | 2,486 |
| | | | | | | | | December 31, 2018 | | | | | | | | Assets | | | | | | | | Cash equivalents | 24,651 |
| | 24,651 |
| | — |
| | — |
| Total assets | $ | 24,651 |
| | $ | 24,651 |
| | $ | — |
| | $ | — |
| | | | | | | | | Liabilities | | | | | | | | Warrant liability | 3,472 |
| | — |
| | — |
| | 3,472 |
| Total liabilities | $ | 3,472 |
| | $ | — |
| | $ | — |
| | $ | 3,472 |
|
The following table reflects the change in the Company’s Level 3 warrant liability (in thousands): | | | | | | | | Warrant liability | Balance at Issuance (January 2018) | | $ | 18,231 |
| Change in fair value | | (14,757 | ) | Warrants exercised | | (2 | ) | Balance at December 31, 2018 | | $ | 3,472 |
| Change in fair value | | (986 | ) | Balance at December 31, 2019 | | $ | 2,486 |
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